Procduct Code: HH80562PH0678M
CPU Speed 2.66 GHz
System Bus Frequency 1066MHz FSB
TDP 130W
Stepping B-3
# of CPU Cores 4
L1 Cache 4x32KB
L2 Cache 8MB (2x4 MB)
CPUID 06F7
Core to bus ratio limit 10:1
Max processor input voltage 1.350V
PECI Enabled Yes
Execute Disable Bit
Process technology: 65 nanometer
582 million transistors

Intel’s new X6700 Core 2 Extreme Quad Core Processor is manufactured on the same 65 nanometer process as that used on earlier Core 2 processors. They plan to move to the 45 nanometer node next year, which should provide more die density, lower heat and more performance for the same die space. The CPU is basically two Core 2 E6700s strapped together, meaning a total of 582 million transistors

The QX6700 has four independent processor cores in a single package, hence the term Quad Core. The CPU has a 1066 MHz FSB, which is the highest FSB available on Intel CPUs at this moment. In reality the QX6700 processor is two Dual -ore CPU dies on the same package, meaning there are effectively two Core 2 CPUs on the same LGA-775 package. Two smaller die, means faster time to market, less engineering time and better yields.

The amount of cache on a processor is important, as the more L2 cache, the more performance you get. This is why the early Celerons didn’t perform well. They had no L2 cache, which meant even though the CPU was clocked at a high for that time speed, performance suffered. The QX6700 has 4 processor cores, with each processor having its own 32KB L1 cache and each pair of processors sharing a 4MB cache the Core 2 CPU.

A new feature of the QX6700 is its Digital Thermal Sensor (DTS) or digital thermometer. The 975XBX board does not support this new feature. Oftentimes with earlier Prescott CPUs and motherboards I’ve had issues with heat causing system failures to occur when the temperature reading of the Winbond chip that regulates it read temperatures way above normal (65C+). With DTS, the thermometer is on the processor itself, allowing for accurate measuring of temperature. The Intel Quiet System Technology included in the 975X chipset, uses the DTS to regulate the system and processor fan speeds. A key benefit of temperature monitoring is that system fans spin only as fast as needed to cool the system, and slower spinning fans means less noise. The test kit did not contain a fan that has FSC (Fan Speed Control). I ran the benchmarks and stability testing with full speed on the fan provided but everyday use was with the fan at 60%.